At least 630 passengers and 54 cruise workers got sick, but not all at the same time.

Some passengers suggested that the outbreak may have been worse than reported.

"They claim there were 600; I think there could have as many as 1,000" sick people on board, passenger Sal Panto Jr. told CNN. "Some people I know didn't bother going down to the infirmary. They weren't feeling well, so they went to the state room. They didn't report it."

After the cruise, Kim Waite told CNN that she discovered the scope of the outbreak when she was taken to a makeshift infirmary in a wheelchair and sick passengers were everywhere, vomiting in buckets and bags. She said she waited three hours to be seen.

"I just started crying," she said. "I couldn't believe it. I was in shock. Because I thought I was the only one that was sick, and then when you see everyone else sick, it really upsets you even more."

Waite said she was anxious to catch a flight back to London with her husband. The tickets will cost them an additional $2,000 on top of what they paid for the cruise and travel.

"I never wanted to go home so much in my life," she said. "I've had enough. I've never slept so much."

Waite said the ship arrived late on the first day of the cruise, and it appeared that there wasn't sufficient time to clean it.

"The seas were so rough, they shut the doors for 2 days," she said. "We had no air. There was no air, no circulation ... and that's why, I think, we got ill."

Danielle Banebianco said she was on a honeymoon, but she and her husband spent a couple of days sick.

"We were looking forward to staying warm and being on our honeymoon and enjoying our time together, and we're never gonna get that back," she said.

Joseph Angelillo told CNN that he became ill, along with his wife, and they were confined to their cabin for three days, unable to eat.

"That was the last thing we wanted to look it," he said of food. "It was terrible, terrible."

Angelillo said entertainers became sick. Shows were canceled. Some sick passengers refused to admit being ill to avoid being confined to their rooms, he said.

"That happened a lot from what I'm hearing," said Angelillo, who sneaked out of his cabin several times for crackers and ginger ale for him and his wife.

He added, "It was atrocious. They tried to do whatever they could do. But once you feel like we were feeling, it wasn't worth it. I doubt if I'll be back."

Angelillo said Royal Caribbean offered sick passengers credit for days they spent confined to their cabins.

"I don't know if I'll ever see the inside of another ship again, while it's in the ocean, put it that way, " he said.

'I lost five pounds'

One passenger was seen being put on a stretcher and taken to ambulance, but the cruise line said in a statement that he was transported to a hospital for a "reason unrelated to norovirus," a common cause of gastroenteritis, which produces vomiting and diarrhea.

"Best cruise of my life," one passenger joked as he left the ship. "I lost five pounds."

Before the ship arrived at port in Bayonne, New Jersey, one frustrated passenger voiced her displeasure with the experience. Passengers disembarked in northern New Jersey shortly before 2 p.m. Wednesday, with some set to stay in area hotels until they can catch flights back home -- days before the Super Bowl will be played there.

"Are we bringing this virus off the ship with us?" asked Shannon Blace, a passenger from Toronto who was traveling with a party of 12 people -- 10 of whom have been sick. "We're all going to hotels all over the New York area. Will we be spreading the virus to the Super Bowl this weekend?"

Blace told CNN via telephone that she was upset and felt as if she had spent a week on a floating prison.

"It's just been a big nightmare," she said. "It feels like (Royal Caribbean) never had a contingency plan in place to handle an epidemic on the ship."

Blace said it was evident early on that many people were sick. She felt the ship should have been turned around.

"On Wednesday night, I was in the dining room and a woman was vomiting into her napkin," she said. "There were people walking around in their pajamas with vomit and diarrhea on them. People were barfing all over the place."

Not all passengers, however, were dissatisfied.

"We had a wonderful cruise, and they were very nice," said Margery Feinstein

On Sunday, five stool samples were sent from the ship to the CDC in Atlanta, where the samples were expected to arrive the next day, CDC sources told CNN. But the arrival of the samples has been delayed because of paperwork issues and the bad weather in the Southeast.

In a statement Wednesday, Royal Caribbean said the entire ship will undergo a "thorough 'barrier' sanitization program ... to make certain that any remaining traces of the illness are eliminated."

"It will be the third aggressive sanitizing procedure the ship has undertaken since we became aware of the issue, and will additionally provide a window of more than 24 hours where there are no persons aboard the ship, which is a significant help," the statement said.

The ship had 3,071 passengers and 1,165 crew members, according to the CDC.

No official cause for illnesses, but norovirus possible

Explorer of the Seas departed Cape Liberty, New Jersey, on January 21 for what would have been a 10-day cruise.

Passengers and crew developed symptoms such as diarrhea and vomiting.

CDC officials boarded the ship in St. Thomas on Sunday to study the outbreak and the response on the voyage back to Cape Liberty.

The cause of the illness was not clear, though the symptoms are consistent with norovirus, the cruise line said.

Noroviruses spread easily and are a common cause of gastroenteritis, which produces vomiting and diarrhea.

"The number of reported new cases of gastrointestinal illness has dropped sharply after a spike in the first days of the cruise, and most guests who fell ill are up and about," the cruise line said Monday.

"The drop in new cases is encouraging. However, it is not unusual in an outbreak to still have smaller, secondary spikes. That is why, after discussions with the U.S. Centers for Disease Control and Prevention and our medical team, we decided the most prudent course for the health of our guests and crew was to bring the cruise home on Wednesday, two days earlier than planned."

The company said all passengers would get a 50% refund and a 50% credit for a future cruise.

Those passengers who were ordered quarantined to their rooms will get an additional credit of one future cruise day for each day in confinement, it said.

"Guests scheduled for the next cruise on Explorer of the Seas can be confident that all possible measures will have been taken to prevent further problems," it added.